The welding electrode consists of two parts: the core and the skin. The paint (coating) is painted uniformly and centripetally on the metal welding core. The electrode type is different, welding core is also different. The welding core is the metal core of the welding rod. In order to ensure the quality and performance of the welding seam, the content of each metal element in the welding core is strictly regulated, especially for the content of harmful impurities (such as sulfur, phosphorus, etc.) The limit is better than the base metal. Electrode coated metal core is called welding core. Welding core is generally a wire with a certain length and diameter. Welding, welding core has two roles: First, conduction welding current, the electric arc generated by the energy into heat, and second, the welding core itself melted as a filler metal and liquid base metal fusion weld.

Pressure coating on the surface of the core coating called the skin. Electrode coating in the welding process plays an extremely important role. In the welding process, the oxygen and nitrogen in the air will invade the molten metal in a large amount, and the metal iron and beneficial elements such as carbon, silicon and manganese will be oxidized and nitrided to form various oxides and Nitride, and remain in the weld, resulting in weld slag or cracks. The gas melted into the weld pool may produce a large number of pores, these factors can make the weld mechanical properties (strength, impact value, etc.) greatly reduced, while making the weld brittle.

Electric arc welding manual welding electrodes consists two parts: coating and the core. Welding, the electrode as an electrode, on the one hand from the current conduction and ignition of the arc, the electrode and the base metal to produce a sustained and stable arc to provide the necessary heat melting. On the other hand, the welding electrode is added as a filler metal to the weld and becomes the main component of the weld metal. Therefore, the composition of the electrode and the quality of welding electrodes, will have a direct impact on the weld metal chemical composition, mechanical properties and physical properties. In addition, the electrode also has a great impact for the stability of the welding process, weld appearance quality, welding productivity.

Welding core is the metal core of the electrode. In order to ensure the quality of the weld, the content of various metal elements in the weld core, there are strict rules. Especially for the harmful impurities (such as sulfur, phosphorus, etc.) have strict restrictions on the quality of metal core welding should be better than the base metal.

There is no coating of the rod electrode is not arc welding. This is because of poor arc stability, large spatter, poor weld formation. After long-term practice, gradually found in the welding core coated with some of the mineral raw materials (ie welding rod coating), electrode performance has been greatly improved.